Pump



Aug. 25, 1925.

l. A. WEAVER PUMP Filed Sept. 24 1925 Patented Aug 25, 1925e UNITE IRAA. WEAVER, OF SPRINGFIELD, ILLINOIS, ASSIGNOR TO WEAVER MANUFACTUR- INGCOMPANY, OF SPRINGFIELD, ILLINOIS, A CORPORATION 0F ILLINOIS.

To all whom t may concern.' Be it known that I, IRA A. IVEAvnR, acitizen of the United States, residing at Springfield, in the county ofSangamon and State of Illinois, have invented certain new and usefulImprovements in Pumps, of which the following is a specification.

My invention relates to pumps and similar appliances, and concernsespecially those adapted for pumping liquids containing abradantmaterials such as grit or sand, or containing acids or other ingredientshaving a tendency to wear or corrode the parts of the mechanism.

One aim of the invention is to provide a structure of this characterwherein means are incorporated to prevent the grit, acid or the likefrom entering the space between the piston or plunger and tie cylinderwithin which it reciprocates, and to this end a suitable liquid underadequate pressure is forced between the two, and since the space or gapis thus occupied by a liquid which has no objectionable qualities, theother liquid and its grit or acid cannot enter and cause the harm orresult in the injury referred to above.

Such a pump is of especially valuable use for dealing with oilscontaining sand, the latter quickly cutting and injuring the metal partsof the usual pumps and rendering them either inefficient or inoperative,the replacement or repair of such parts being a relatively expensiveitem.

A further purpose of the invention is to supply a pump having thecapabilities specified which is simple in structure, which is economicalto manufacture, and which operates effectively and eiciently.

In order to enable those skilled in this art to have a full and completeunderstanding of the invention, and its various structural andfunctional advantages, in the-ac-7 companying drawing, forming a part ofthis specilication, and throughout the views of which like referencecharacters refer to the same parts, I have shown a desirable andpreferred embodiment of the invention, although the latter issusceptible of many other embodiments.

In this drawing,-

Fig. 1 is a central, vertical, longitudinal section through the improvedpump; and

Fig. 2 is a plan view of the double piston 0r plunger employedrl thepump..

PUMP.,

Serial No. 664,484.

By reference to this drawing, it will be seen that the pump-cylinder 11has two parts 12 and 13 of different internal diameter, the former beingof slightly less diameter than the latter.

The smaller section of such cylinder is provided with an inlet laequipped with a valve 15, and also it is equipped with an outlet 16supplied with a control valve 17.

rIhe larger-diameter section of such cylinder has an inlet 18 fittedwith a valve 19, as is clearly illustrated in F ig. 1.

The double or duplex piston comprises a portion 21 of smaller diameterand a section 22 of larger diameter, the two being connected together byan intermediate part 25 of a diameter smaller than that of the section22.

The portion 12 of the cylinder accommodates the part 21 of the piston orplunger, and the larger portion 22 of the piston eX- tends out of theend of the cylinder, a pressure-tight connection with the latter beingeffected by means of a gasket or packing 23.

A rod or shaft 24 connected to any suitable source of power is the meansprovided for reciprocating the plunger or piston in the two-partcylinder, and such driving means may be of any appropriate type orstyle.

A passage 26 extends longitudinally through the middle part of theduplex piston, and it has a conduit or opening 27 eX- tended through theside or top thereof, thereby bringing the passage 26 into communicationwith the part 13 of the cylinder.

Passage 26 connects with a compartment 28 in the portion 21 of thepiston, and such chamber, by means of a plurality of holes 29, connectswith a groove 31 around the periphery of the portion 21 of the pistonnear one end thereof, that partof the piston 32 between the groove andthe end of the piston being of slightly less diameter than the main body21.

Chamber 28 accommodates a valve 33 designed to Vopen and close theconnection between the passage 26 and the chamber 28, such valve beingmounted on the end of a stem 3a extending through the opening 26 into achamber 35 in the larger part of the piston or plunger, such chamberhousing a coiled spring 36 connected at one end to the rod 34 and at itsother end to a threaded stem 37 extended out through a passage 41 in theend wall of the piston and being supplied externally with an adjustingnut 3 in a cavity in a yoke forming the connecting means between the rod2st and the piston proper.

lt will be clear therefore that by manipulation of the nut 38 thetension of the spring 8G may be governed, which in turn controls theopening and closing of the valve rllhe operation of this pump occurspractically as follows:

lWhen the double piston is sliding to the right as the parts are viewedin Fig, l, treating a suction or partial vacuum in the cylinder-chamber12, the valve 15 opens and permits the sand-laden oil to enter thatsection of the cylinder.

Also during such right-hand movement of the piston, the valve 19 opensinwardly, admitting an oil or other liquid 'free from deleteriousingredients into the larger part 13 of the cylinder, this admission ofthe liquid through the connection 18 beingl due to the fact that thepart 22 of the piston is of greater cross-sectional area than theportion 21 thereof.

During the. stroke of the duplexV piston to the left, the valve 15remains closed and the contents of the chamber 12 are forced out throughthe discharge pipe i6, the valve 1T being automatically opened for thispurpose by reason of the pressure in the cylinder.

Also during such travel of the double piston, the larger portion orsection thereifif, constituting a secondary pump, places on the oil,water or other liquid or fluid in the part 13 of the cylinder a pressuregreater than that created by the pumping action in the smaller cylindersection 12, thus causing a part of such liquid to be forced as `asealing medium between the smaller piston section 21 and thecorresponding cylinder wall.

If there were no such leakage or similar relief around the packing 23 atendency to break or rupture the cylinder would be developed.

The valve constitutes a safety valve, and when it opens under thedeveloped pressure it permits a part of the. higher-pressure liquid orfluid to discharge through the passages 27, 2G, 28 and 29 .into thegroove 81, from which it finds egress or discharge around the part 32 ofthe piston into the chamber 12, such delivery tending to scavenge orclean the cylinder wall in advance of the movement of the piston overit.

Thus by these two co-operating means or functions, the liquid and itsobjectionable ingredients, abradant, corrosive or otherwise, in thecylinder chamber 12 are effectively prevented from access to the spacebetween the piston and cylinder wall, thereby preserving these againstdamage or injury or excessive wear.

Thus this simple, duplex pump mechanism.

assures the eflicient pumping action of liquids which would otherwisebring about serious wear or corrosion of the parts of the mechanisminvolved, and although this device has been described in connection withliquids, it is obvious that fluids other than liquids could bcsatisfactorily used in the appliance.

A pump of this type is of especial value for pumping the heavy slushthat is used in drilling oil wells with rotary outlits, such tlushcontaining mud and water at a high pressure which travels down thehollow drill-rods and aids in bringing the cuttings to the surfacebetween the rods and the holes being bored. The object of forcing suchslush under pressure is te seal the pores of the soil so that the holewill remain open while the drilling operation is going on and until thecasing` is set.

Obviously, if there is much grit in the slush used, the packing of anordinary pump cuts out very quickly and the pump parts themselves wearrapidly.

ln the appliance described, owing to the greater pressure imposed on thesealing liquid, it is forced into the space between the piston andcylinder under positive pressure, causing some. of the liquid to passforwardly between the piston or plunger and the cylinder wall, therebypreventing sand and grit from entering such space. lf the lit of theplunger were close and the pacling gland did not leak, it would beneces.` to provide a safety valve for the surplus sealing liquid.

ln the present appliance, the safety valve is arranged within theplunger so that an excess amount of sealing liquid may be drawn in ateach stroke, the safety valve permitting the discharge of this surplusin the groove directly in front of the main body of the piston, whichdelivery ten ds to wash any grit from the cylinder in advance of theplunger or piston.

l claim 1. In a pump, the combination of a cylinder, a reciprocatorypiston therein, and means to force a sealing fluid between said pistonand the cylinder wall during the discharge stroke only of the piston andat a pressure greater than that of the fluid which the piston pumps.

2. ln a pump, the combination of a cylinder, a reciprocatory pistontherein, means to force asealing fluid between the piston and thecylinder wall throughout. the length of the former, and means to force asealing detrimental effects on the pump, means to force a sealing fluidsubstantially free from such qualities between the piston and thecylinder wall, and means to force a sealing fluid substantially freefrom said qualities between the piston and the cylinder wall at a pointnear the inner end of the piston whereby such latter fluid tends toclean the cylinder wall in advance of the piston.

Il. In a pump, the combination of a cylinder, a reciprocatory pistontherein to pump a fluid having qualities tending to produce detrimentaleffects on the pump, means to force a sealing fluid substantially freefrom such qualities between the piston and the cylinder wall, and meansto force a sealing fluid substantially free from such qualities betweenthe piston and the cylinder wall at a point near the inner end of thepiston whereby such latter uid tends to clean the cylinder wall inadvance of the piston, both sealing fluids being at a pressure greaterthan that of the fluid which the piston pumps.

5. In a pump, the combination of an openended cylinder, a pistonreciprocatory therein and projecting out of said open end, packing meansbetween the cylinder wall and the piston, means producing` a fluidpressure in the cylinder between said packing means and the inner end ofthe piston greater than the pressure of the fluid pumped by the pistonwhereby a portion of such fluid is forced between the piston and thecylinder wall as a sealing medium, and means including an automaticvalve for delivering a portion of such fluid under pressure between saidcylinder wall and piston at a point near the inner end of the latter,whereby such latter fluid tends to clean the cylinder wall in advance ofthe piston.

6. In a pump, the combination of an openended cylinder, a pistonreciprocatory therein and projecting out of said open end, said pistonhaving a groove around its periphery near its inner end, packing meansbetween said cylinder wall and said piston, means producing a fluidpressure in said cylinder between said packing means and the inner endof said piston greater than the pressure of the fluid pumped by saidpiston, whereby aportion of such greater pressure fluid is forced as asealing medium between the cylinder wall and the piston, and meansincluding an automatic valve and a passage in said piston to deliver aportion of such fluid under pressure to said groove to clean thecylinder wall in advance of the piston.

7. In a pump, the combination of a cylinder having` a smaller diametervsection and a larger diameter section, a piston reciprocatory in saidcylinder having corresponding smaller and larger diameter portions,valved inlet and outlet for said smaller cylinder section, and a valvedinlet for said larger cylinder section, the discharge from said lattersection being the space between said smaller diameter cylinder wall andsaid smaller portion of the piston.

8. In a pump, the combination of a cylinder having a. smaller diametersection and a larger diameter section, and a piston reciprocatory insaid cylinder having corresponding smaller and larger diameter portionswhereby a fluid placed under pressure by the reciprocation of saidlarger diameter portion of the piston is forced as a sealing mediumbetween the smaller section of the cylinder and the smaller portion ofthe piston.

9. In a pump, the combination of a cylinder having a smaller diametersection and a larger diameter section, a piston reciprocatory in saidcylinder having corresponding smaller and larger diameter portions,valved inlet and outlet for said smaller cylinder section, a valvedinlet for said larger cylinder section and a valved connection from saidlarger cylinder section through said piston to a point between thesmaller portion of said piston and the smaller diameter cylinder wallnear the inner end of the piston, whereby the discharge of fluid underpressure from said larger cylinder section takes place partly throughthe space between the smaller diameter cylinder wall and the smallerportion of the piston and to the point specified near the inner end ofthe piston.

10. In a pump, the combination of a cylinder having two sections ofsmaller and larger diameters, a piston reciprocatory in said cylinderhaving two portions of smaller and larger diameters, a groove around theperiphery of the smaller section of said piston near the inner end ofthe latter, said piston having a passage connecting with said groove, avalve in said piston controlling said passage, and means whereby thereciprocation of the large section of the piston forces a fluid throughsaid passage into said groove under a pressure greater than thatproduced in the cylinder by the movements of the smaller section of saidpiston, a portion of said fluid being forced as a sealing medium intothe space between the smaller part of the piston and the smaller sectionof the cylinder wall.

In witness whereof I have hereunto set my hand and seal.

IRA A. WEAVER. [n s]

